IRREPLACABLE: Former Arsenal chairman Peter Hill-Wood thinks Arsene Wenger will be very difficult to replace [GETTY]

Wenger takes charge of his 1,000th Gunners game, at Stamford Bridge tomorrow, and Hill-Wood - who stepped down after 31 years as chairman in June due to ill health - insists he will be a tough act to follow.

But he dismissed any prospect of Chelsea boss Jose Mourinho succeeding the Frenchman when he finally calls it quits.

Asked if the difficulties David Moyes had endured stepping into Sir Alex Ferguson's shoes at Manchester United this season, has made the thought of losing Wenger even more daunting, Hill-Wood said: "Yes, but luckily it is not my decision.

DIFFICULT TASK: Hill-Wood is happy he doesn't have the job of finding Wenger's replacement [PA]

“It will be extremely difficult - I dread to think who is coming in.”

Peter Hill-Wood

"It will be extremely difficult - I dread to think who is coming in.

"If we were to lose Arsene it would be a nightmare

"There is nothing obvious. I am sure Arsene will have some input.

"He has an enormous amount of knowledge and has developed a lot of really excellent players, who, overall, weren't that distinguished when they came to us.

"Many of them became household names at Arsenal. Thierry Henry is a very good example, also Cesc Fabregas, Patrick Vieira and Robin van Persie."

Wenger has never beaten Mourinho in 10 attempts and Hill-Wood said: \"I think it would be a great achievement if Arsene can get his first win against Mourinho."

But he laughed off the idea of the outspoken and controversial Mourinho - who has often targeted Wenger in his attacks - ever taking the helm at The Emirates.

"I wouldn't find him at all easy as manager," he said. "I think it is most unlikely."

HE'LL HAVE A SAY: Hill-Wood believes Wenger will say in who takes over from him at the Emirates [GETTY]

But he refused to rule out Everton boss Roberto Martinez, who Starsport revealed last week is on the Gunners' long-term radar.

Hill-Wood also assured fans they had nothing to worry about, despite Wenger being out of contract at the end of the season.

"I have spoken to Ivan Gazidis he is very confident that there isn't a problem, that he just doesn't want to sign up right now. That's all.

"It's not a question of somebody dangling great riches in front of him. That actually doesn't interest him.

"I don't think his enthusiasm has diminished at all. He doesn't think his job is finished yet."